1. Field of the Invention
The present invention relates to an image reading method for reading the image of transmission originals such as a developed photograph film, an image reading apparatus thereof, and a memory medium for storing a control program to control the image reading apparatus.
2. Related Background Art
In a conventional image reading apparatus (film scanner), transmission originals such as a micro film and a photograph film is irradiated by a lighting optical system from the back of the transmission originals and the transmitted light is projected to the image forming plane of a photoelectric conversion element via a projection optical system to form an image, thereby performing photoelectric conversion by the photoelectric conversion element to convert information of the transmission original into electrically.
In such the conventional apparatus, however, foreign matters adhering to the lighting optical system and projection optical system and foreign matters and flaws on the transmission original appear as black spots on the read image data, and as a result there arises a problem that the image is deteriorated.
FIGS. 34A and 34B are schematic diagrams showing the influence of the above-described foreign matters and flaws to the image data and output image, FIG. 34A shows that the transmission original is a reversal film, and FIG. 34B shows that the transmission original is a negative film.
In FIG. 34A, the image (positive image) of the reversal film on which an object is photographed is read by a scanner (film scanner) as an image reading apparatus, and the read image signal is subjected to gamma correction, and outputted as the positive image visible to human eyes.
Moreover, in FIG. 34B, the image (negative image) of the negative film on which the object is photographed is read by the scanner (film scanner) as the image reading apparatus, the read image signal is subjected to reversal processing, and subsequently to the gamma correction (image processing), and is outputted as the positive image visible to human eyes.
As shown in FIGS. 34A and 34B, whichever the transmission original is the reversal film or the negative film, the foreign matters/flaws appear as the black spots on the image signal and output image (positive image), when the transmission original is converted to the image signal and read by the scanner (film scanner) as the image reading apparatus.
As a result, for the reversal film, as shown in FIG. 34A, since the image signal is subjected to the image processing such as the gamma correction and outputted onto an output apparatus such as a printer as it is, the influences of the foreign matters/flaws appear as the black spots on the output image (positive image) as they are.
On the other hand, for the negative film, as shown in FIG. 34B, since the image signal read by the scanner is subtracted from the image signal read at a full level to convert the negative image to the positive image, the influences of the foreign matters/flaws appear as white luminous spots on the output image (positive image).
To solve the problem, the transmittance characteristic of the transmission original to infrared light has been noted, and there has already been proposed an image reading apparatus (film scanner) for detecting only the foreign matters/flaws causing the image deterioration as described above, by the infrared light transmitted through the transmission original, and applying the correction to the read image data with the information of the detected foreign matters/flaws.
FIG. 35A shows a visible image reading system, and FIG. 35B shows an infrared image reading system. Moreover, in the drawings, numeral 31 denotes an original, 32 denotes an image plane as a light receiving element such as CCD, and 33 denotes an image forming lens for forming the image of the original 31 on the image plane 32.
In FIG. 35A, in order to read the image of the original 31, the image of the original 31 irradiated with visible light is read in an appropriate image forming state. On the other hand, in FIG. 35B, the infrared light is radiated to the image of the original 31 to read the defects such as the foreign matters and flaws on the original.
In this manner, the defects in the image information read by the visible light are corrected by the range information of the foreign matters and flaws on the original read by the infrared light.
One example is disclosed in Japanese Patent Publication No. 7-97402 (hereinafter referred to as a first related art), Japanese Patent No. 2559970 (hereinafter referred to as a second related art) and Japanese Patent Publication No. 6-78992 (hereinafter referred to as a third related art).
In the first related art, the image information around the pixel recognized as the foreign matter/flaw is appropriately selected to perform data correction.
Moreover, in the second related art, in addition to the image correction from the image data around the pixel recognized as the foreign matter/flaw, the image correction is also performed based on the infrared-light data of the area of the pixels recognized as the foreign matters/flaws, and further a plurality of image correction methods are adaptively used in accordance with the level of the infrared-light data.
Furthermore, in the third related art, in order to correct the positional deviation of the image forming plane by the wavelength difference between the visible light and the infrared light, the optical path length can be changed for each light to be formed into the image.
However, in the related art, when the optical path length is changed to correct the positional deviation of the image forming plane, a relative ratio of a distance between a transmission original surface and an optical system main point position to a distance between the optical system main point position and the image forming plane changes, then the visible light is different from the infrared light in image magnification, and it is disadvantageously difficult to accurately grasp the position of the foreign matter/flaw. Thus, the correction of the foreign matter/flaw is incorrect, and the image grade is sometimes deteriorated by performing the correction processing.
Moreover, in the related art described above, when the foreign matter/flaw area is grasped by the infrared light, and if the image data is extracted with the same resolution as that of the scan by the visible light, the time or memory required for extracting the image data is simply doubled, and further the time required for correcting the image data or the memory capacity is also necessary by the considerable amount, thereby causing a problem that there is a difficulty in operationality for performing the correction processing of the foreign matter/flaw.
Furthermore, in the related art described above, since the correction of the foreign matter/flaw on the transmission original is performed in the system, that is, in the system controller, an operator cannot recognize the progress. The operator simply needs to see the corrected image with respect to the image of the transmission original having the foreign matter/flaw to recognize that the correction has been performed. Moreover, since the foreign matter/flaw correction system is not universal for all cases, and conversely the image is sometimes deteriorated by performing the correction, the operator needs to recognize the progress also to judge whether or not to correct the foreign matter/flaw. In the related art, however, the operator cannot easily compare or recognize the foreign matter/flaw correction effects, and it is disadvantageously difficult to easily select an image from an image finally obtained before performing the foreign matter/flaw correction and an image after such the performing.
The present invention has been developed in consideration of the above-described problems of the related arts, and a first object thereof is to provide an image reading method and apparatus in which the position of a foreign matter/flaw can exactly be grasped.
Moreover, a second object of the present invention is to provide an image reading method and apparatus in which foreign matter/flaw correction can exactly be performed without complicating a circuit constitution or without increasing the necessary memory capacity and processing time.
Furthermore, a third object of the present invention is to provide an image reading method and apparatus in which an operator can easily compare and recognize the effects of the foreign matter/flaw correction, and can easily select an image from an image finally obtained before performing the foreign matter/flaw correction and an image obtained after such the performing.
Additionally, a fourth object of the present invention is to provide a memory medium for storing a control program to control the image reading apparatus of the present invention.
To attain the first object, according to the present invention, there is provided an image reading method of forming an image on a transmission original illuminated with visible light and infrared light by an image forming optical system and reading the image by reading means, comprising an image forming magnification correction step of correcting a difference between an image forming magnification of a visible-light image and the image forming magnification of an infrared-light image of the image forming optical system.
Moreover, to attain the first object, according to the present invention, there is also provided an image reading apparatus for forming an image on a transmission original illuminated with visible light and infrared light by an image forming optical system and reading the image by reading means, comprising image forming magnification correction means for correcting a difference between an image forming magnification of a visible-light image and the image forming magnification of an infrared-light image of the image forming optical system.
Furthermore, to attain the second object, according to the present invention, there is provided a memory medium which stores a control program to control an image reading apparatus for forming an image on a transmission original irradiated with visible light and infrared light by an image forming optical system and reading the image by reading means and which is readable by information reading means, the control program comprising an image forming magnification correction module for correcting a difference between an image forming magnification of a visible-light image and the image forming magnification of an infrared-light image of the image forming optical system.
Additionally, to attain the first object, according to the present invention, there is provided an image reading method for irradiating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means, comprising: an infrared-light image extraction step of focusing by a visible-light image and subsequently changing an optical path length to extract an infrared-light image; and an area determination step of correcting an image magnification change caused during the extraction of the infrared-light image and determining a correction requiring area.
Moreover, to attain the first object, according to the present invention, there is provided an image reading apparatus for irradiating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means, comprising: infrared-light image extraction means for focusing by a visible-light image and subsequently changing an optical path length to extract an infrared-light image; and area determination means for correcting an image magnification change caused during the extraction of the infrared-light image and determining a correction requiring area.
Furthermore, to attain the first object, according to the present invention, there is provided an image reading method comprising: a light emission step of emitting visible light and infrared light to illuminate a transmission original; an image forming step of forming light transmitted through the transmission original into an image by an optical system; an optical path length change step of changing the optical path length of an optical system for forming the light transmitted through the transmission original into an image; a focusing step of using the optical path length change step to perform a focusing operation; alight detection step of detecting the light transmitted through the optical system; a storing step of storing a light detection result in the light detection step; a calculation step of comparing and calculating contents stored in the storing step; a judging step of judging from the light detection result in the light detection step whether an area requires correction or not; and a correcting step of correcting image data in the correction requiring area, wherein when the transmission original is illuminated with the visible light, a focused state is obtained by the focusing step, and when the transmission original is illuminated with the infrared light, the optical path length is changed only by a predetermined amount predetermined in the optical length change step, from the focused state.
Additionally, to attain the first object, according to the present invention, there is provided an image reading apparatus comprising: light emission means for emitting visible light and infrared light to illuminate a transmission original; an optical system for forming the light transmitted through the transmission original into an image; optical path length change means for changing the optical path length of the optical system; focusing means for using the optical path length change means to perform a focusing operation; light detection means for detecting the light transmitted through the optical system; storing means for storing a light detection result by the light detection means; calculation means for comparing and calculating contents stored by the storing means; judgment means for judging from the light detection result by the light detection means whether an area requires correction or not; and correction means for correcting image data in the correction requiring area, wherein when the transmission original is illuminated with the visible light, a focused state is obtained by the focusing means, and when the transmission original is illuminated with the infrared light, the optical path length is changed only by a predetermined amount predetermined by the optical length change means, from the focused state.
Moreover, to attain the second object, according to the present invention, there is provided an image reading method of irradiating a transmission original with visible light and infrared light and reading a transmission original image by reading means, comprising a reading resolution setting step of allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.
Furthermore, to attain the second object, according to the present invention, there is provided an image reading apparatus for irradiating a transmission original with visible light and infrared light and reading a transmission original image by reading means, comprising reading resolution setting means for allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.
Additionally, to attain the second object, according to the present invention, there is provided an image reading method comprising: a light emission step of emitting visible light and infrared light to irradiate a transmission original; a light detection step of detecting the light transmitted through the transmission original; a storing step of storing a light detection result in the light detection step; a calculation step of comparing and calculating contents stored in the storing step; a judgment step of judging from the light detection result by the light detection step whether an area requires correction or not; a correction step of correcting image data in the correction requiring area; and a reading resolution setting step of allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.
Moreover, to attain the second object, according to the present invention, there is provided an image, reading apparatus comprising: light emission means for emitting visible light and infrared light to irradiate a transmission original; light detection means for detecting the light transmitted through the transmission original; storing means for storing a light detection result by the light detection means; calculation means for comparing and calculating contents stored by the storing means; judgment means for judging from the light detection result by the light detection means whether an area requires correction or not; correction means for correcting image data in the correction requiring area; and reading resolution setting means for allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.
Furthermore, to attain the third object, according to the present invention, there is provided an image reading method of irradiating a transmission original with visible light and infrared light, reading a transmission original image by reading means, detecting an area of a correction object from image data by the infrared light, and correcting the detected correction object, comprising a display step of displaying images obtained before and after the correction.
Additionally, to attain the third object, according to the present invention, there is provided an image reading apparatus for irradiating a transmission original with visible light and infrared light, reading a transmission original image by reading means, detecting an area of a correction object from image data by the infrared light, and correcting the detected correction object, comprising display means for displaying images obtained before and after the correction.
Moreover, to attain the third object, according to the present invention, there is provided an image reading method comprising: a light emission step of emitting visible light and infrared light to illuminate a transmission original; a light detection step of detecting the light transmitted through the transmission original; a storing step of storing a light detection result in the light detection step; a calculation step of comparing and calculating contents stored by the storing step; a judgment step of judging from the light detection result by the light detection step whether an area requires correction or not; a correction step of correcting image data in the correction requiring area; and a display step of displaying a first image obtained before the correction is performed by the correction step and a second image obtained after the correction is performed by the correction step.
Furthermore, to attain the third object, according to the present invention, there is provided an image reading apparatus comprising: light emission means for emitting visible light and infrared light to irradiate a transmission original; an optical system for forming the light transmitted through the transmission original into an image; light detection means for detecting the light transmitted through the optical system; storing means for storing a light detection result by the light detection means; calculation means for comparing and calculating contents stored by the storing means; judgment means for judging from the light detection result by the light detection means whether an area requires correction or not; correction means for correcting image data in the correction requiring area; and display means for displaying a first image obtained before the correction is performed by the correction means and a second image obtained after the correction is performed by the correction means.
Additionally, to attain the fourth object, according to the present invention, there is provided a memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, the control program comprising: an infrared-light image extraction module for focusing by a visible-light image and subsequently changing an optical path length to extract an infrared-light image; and an area determination module for correcting an image magnification change caused during the extraction of the infrared-light image and determining a correction requiring area.
Moreover, to attain the fourth object, according to the present invention, there is provided a memory medium which stores a control program to control an image reading apparatus for irradiating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, the control program comprising: a light emission module for emitting the visible light and the infrared light to illuminate the transmission original; an optical path length change module for changing an optical path length of an optical system for forming the light transmitted through the transmission original into an image; a focusing module for using the optical path length change module to perform a focusing operation; a light detection module for detecting the light transmitted through the optical system; a storing module for storing a light detection result by the light detection module; a calculation module for comparing and calculating contents stored by the storing module; a judgment module for judging from the light detection result by the light detection module whether an area requires correction or not; and a correction module for correcting image data in the correction requiring area, wherein when the transmission original is illuminated with the visible light, a focused state is obtained by the focusing module, and when the transmission original is illuminated with the infrared light, the optical path length is changed only by a predetermined amount predetermined by the optical path length change module, from the focused state.
Furthermore, to attain the fourth object, according to the present invention, there is provided a memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, the control program comprising a reading resolution setting,module for allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.
Additionally, to attain the fourth object, according to the present invention, there is provided a memory medium which stores a control program to control an image reading apparatus for illuminating a transmission original with visible light and infrared light and reading an image on the transmission original by reading means and which is readable by information reading means, the control program comprising: a light emission module for emitting the visible light and the infrared light to illuminate the transmission original; a light detection module for detecting the light transmitted through an optical system for forming the light transmitted through the transmission original into an image; a storing module for storing a light detection result by the light detection module; a calculation module for comparing and calculating contents stored by the storing module; a judgment module for judging from the light detection result by the light detection module whether an area requires correction or not; a correction module for correcting image data in the correction requiring area; and a reading resolution setting module for allowing a reading resolution by the visible light to differ from the reading resolution by the infrared light.
A fifth object of the present invention is to provide an image reading apparatus which miniaturizes and simplifies the apparatus and which can adequately correct defects such as foreign matters and flaws on an original.
To attain the above-described object, according to the present invention, there is provided an image reading apparatus comprising a visible-light filter for forming a visible-light original image; an infrared-light filter for forming an infrared-light original image; and correction means for correcting a defect of the visible-light original image based on the infrared-light original image, wherein thickness values of the visible-light filter and the infrared-light filter are set so that an original image forming error caused by a difference in wavelength between visible light and infrared light is corrected.
Moreover, there is provided another image reading apparatus comprises: a visible-light filter for forming a visible-light original image; an infrared-light filter for forming an infrared-light original image; signal processing means for correcting an original image magnification error caused by a difference in wavelength between visible light and infrared light; and correction means for correcting a defect of the visible-light original image based on the infrared-light original image.
Furthermore, there is provided another image reading apparatus comprises: a visible-light filter for forming a visible-light original image; an infrared-light filter for forming an infrared-light original image; and correction means for correcting a defect of the visible-light original image based on the infrared-light original image, wherein thickness values of the visible-light filter and the infrared-light filter are set so that an original image magnification error caused by a difference in wavelength between visible light and infrared light is corrected.
Additionally, there is provided still another image reading apparatus comprises: a visible-light filter for forming a visible-light original image; an infrared-light filter for forming an infrared-light original image; and correction means for correcting a defect of the visible-light original image based on the infrared-light original image, wherein thickness values of the visible-light filter and the infrared-light filter are set so that an original image forming error and magnification error caused by a difference in wavelength between visible light and infrared light are corrected.
Moreover, there is provided still further image reading apparatus comprises: a visible-light filter for forming a visible-light original image; an infrared-light filter for forming an infrared-light original image; an original image forming lens which moves to correct at least one of an original image forming error and a magnification error caused by a difference in wavelength between visible light and infrared light; and correction means for correcting a defect of,the visible-light original image based on the infrared-light original image.
Other objects and characteristics of the present invention will be apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.